1) The dolomite lime. Magnesium tightens soil whereas Calcium loosens it up. Dolomite lime is around 2:1 Ca:Mg which you don't want... In soil we like to see at least a 7:1 Ca:Mg ratio to keep soil structure nice and loose.

Not to mention, Premeir Peat already comes loaded with Magnesium out of the bag. Around 14%.. definitely don't need anymore.

Consider switching out the dolomite for some ag lime or even some oyster shell flour. A bag of dolomite is cheap, no doubt, but a bag of ag lime is only around 9 dollars more in my area. The benefit outweighs the cost in every aspect.

2) 1/3 compost on the base mix is too much imo, it clogs the soil and makes it heavy and mucky from the start, pushing oxygen out. Consider cutting your compost down to somewhere around 10-20% at the start. The microbes will do better with more oxygen.

I have some recycled FFOF that I also use and its much more airy or light and when I water it the water doesn't pool at the top as much as the soil I built from scratch

the recycled fox farm also dries out quicker or holds moisture for less time than the DIY soil

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More aeration.

I almost always end up adding more perlite and pine bark fines to reamends.

All those amendments, top dressings, VC and stuff break down and create more humus and a more dense mix as time goes on. Especially that 30% compost that's so touted. I totally agree with MR on that point and add no compost at all and keep the fresh VC to ~10%.

That 1/3 - 1/3 - 1/3 ratio is at best a suggestion or starting point and people treat it as gospel. Then usually lack growing experience to tell when something is out of whack. I know you're mainly from hydro background, but still had enough experience to know water pooling on the surface is something out of kilter and ask for reasons/solutions.

The dolomite? No argument with MR, but I've just never seen issues in CONTAINER MIXES. The red clay of my soil gardens gets treated differently, bucause compaction issues do happen there. But, IMO, that's more of a agriculture vs horticulture thing. Problems that you may encounter in soil but not in container mixes and vice versa.

The funny thing is, I never even encountered dolomite till I moved to SC. SoFl is almost all solid calcitic limestone from ancient coral beds and dolomite was the expensive stuff. The Ag lime was ~$25 a dump truck load.

BTW, like you, I found that the 1cup/cf of dolo wasn't buffering the pH quite enough and have since bumped it up to 1 1/2 cups/cf. After buffering gypsum is used as a Ca source.

In another post, I'll give you my base mix amounts which may help explain all this blathering some.

The dolomite? No argument with MR, but I've just never seen issues in CONTAINER MIXES. The red clay of my soil gardens gets treated differently, bucause compaction issues do happen there. But, IMO, that's more of a agriculture vs horticulture thing. Problems that you may encounter in soil but not in container mixes and vice versa.

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First, No debate here, just want to touch down on a few topics..

I understand where you're coming from completely in regards to this. Out in the real world (ag) its deemed a lot more important to keep track of Ca:Mg ratios as we don't have consistent types of soil with the same amounts of aeration you'd find in a container mix. Basically, the aeration is what saves us in our situation. Mixed with the fact that our peat mixes are half the weight of most field soils..

I used to run dolomite lime in my mixes years ago and no matter what I'd do I'd always end up with a hard crusty surface on the top of my pot.

Did some soil testing to find out my Mg was sky high. Started using ag lime and haven't had a problem since. Same result with all the bagged soils that used dolomite as well.

The more I practice using different mixes the more i want to go back to the good ol' Tom Hill mix. Lots of Calcium and Lots of Phosphorus

@MR
One quick question since I've spent nearly the last hour searching. Where did you get the 14% Mg amount in the Premier peat moss? I like to do my own research, but my Google-Fu seems weak today. I've used Premier for well over 40 years, but have never seen that tidbit and I'm really curious.

One thing I have noticed with dolo is that the Ca/Mg ratios can vary a good bit depending on location of the mine. Got most of this from a geology thing I was reading on different marbles and how they are formed. Never knew they were another form of limestone and why certain ones were so localized.

A quick tip for the crusty surface (I get it when I get too happy with a VC top dress). I get the gallon jug of Aloe Vera juice at Wal Mart for $6.44 and use a heavy 1/4 cup/gallon to saturate it. Still crusty, but doesn't impede the water anymore. I'll crunch it up as I feel energetic and a mulch helps as well. My mulch is a blend of perlite and pine bark fines, discovered by accident, that works well for me outside, but drives the organophobes crazy. LOL

I learned this by rote and sweat labor over 45 years ago in 1972. There were no written recipes and 20 years before the word internet was even heard. Everything is geared to mixing in a standard (6cf), wheelbarrow. Altered slightly over the years, but nothing drastic and I will note the old and new.

VERY similar to LC's #1 mix and he probably learned it like I did, from a old timer who was kind enough to pass on the information for the price of the shovel work making a few batches of mix.

I use 5gal buckets for rough measurements so the wheelbarrow isn't overfilled, but the final measurements are always eyeballed till it looks and feels right.

BTW, 5 gallons in a 5gal bucket is a few inches from the top, so filling it to the top edge is a bit more than 5 1/2 gallons.

Peat moss: After 'expanding' by either screening or just rubbing it between your hands to remove any clumps or still compressed moss, I'll fill 1 1/2 buckets, ~7.5 gallons or 1cf. A bit more or less is fine, don't stress exact measurements.

Perlite: Full to the top 5gal bucket. After eyeballing at the end there is usually ~6 gallons of perlite.

Pine Bark fines: ~3 gallons or a bit less. Back when, you could get actual bags labeled Pine Bark Fines as a graded size and no extra cost. I've never seen them since moving to SC. The closest thing is pine bark mulch and I run this through a 1/2" screen to get what I like. They should be flakes, fingernail size or smaller. No big chunks or long stringy stuff. Back when, the mix called for 3 shovelfuls.

EWC: ~2 gallons. I use homegrown fresh VC and it is very dense and very rich. Adding much more than that would just turn the mix to mud. Have no idea about bagged stuff, have never used it. Back when, the mix called for 2 shovelfuls of sheep manure. Haven't seen that in ages. It got outlawed in Fl and we used cow manure instead.

Lime: Healthy 3 cups of dolomite. Found that the 1cup/cf amount wasn't buffering the pH enough and bumped it up. The total of this mix ends up a bit over 2cf (~18 gallons), so a heaping 3 cup scoop works well for me. Back when, the mix called for 1 or 2 shovelfuls of 'screenings'. This was Oolitic limestone that passed through the finest screen at a aggregate quarry. The $25/dump truck load mentioned elsewhere. Very slow release. There was some 'flour' in there, but most was so coarse it took years to release. Mainly, we top dressed our lawns with it and in the mix it mostly just added some weight to keep pots from blowing over.

Anyway, that's it, my base mix. From here, the choice and amounts of amendments is pretty open and up to the individual grower, but it sure helps having a consistant base to work from when you experiment.

Black Kow manure is very useful and can replace EWC 1/1 if need be or even if not. Black Gold from garden and hardware stores is 80%+ castings with peat moss. A great bulkier compost is Back to Nature Cotton Burr Compost. Fantastic stuff inside or out. It's also the only brand that I will use. Always the same and been using for ten years. Local nurseries use this themselves.

maybe 1 gallon compost an additional 1/2 gallon perlite and an additional 1.5 gallons peat? (or would that be too much peat)

when I recycle it I will be using gypsum (not lime)

plus im going to add some biochar to this soil also

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How about zero compost, 1 gallon perlite and a light gallon of peat? The biochar will also help with aeration.

*I* feel that the compost is a big factor in making the mix too dense and the peat to a much less degree.

The perlite provides lots of little air holes (?), to keep stuff from compacting too much.

You are on the right track about the guanos. I noticed when I moved away from blood meal and more to seed meals how the density of the mix increased over time. Plus, when I used say 1/2cup of blood meal, I would be using a cup or more of a seed meal for the same purpose. When the blood was depleted, it was gone. When the seed meals were depleted there was still some sludge/humus/something left behind and all that something adds up. Have next to zero experience with guano, so can't comment there.